This example describes a video sharing service. The individual videos are
organized in directories. Every directory has an owner and every video has the
same owner as it's parent directory. The owner has elevated privileges about the
video files that are not modeled individually in Ory Keto. The only other
privilege modeled in this example is "view access." Every owner has view access
to their objects, and this privilege can be granted to other users as well. The
video sharing application interprets the special
* user ID as any user,
including anonymous users. Note that Ory Keto does not interpret this subject
any differently from other subjects. It also does not know anything about
directory structures or induced ownership.
The "Keto client" is the application interacting with Keto. In this case we refer to the video sharing service backend as the Keto client.
First, install Keto.
Now you can start the example using either
docker-compose or a bash script.
The bash script requires you to have the
keto binary in your
Alternatively, use Docker to automatically get the required images.
At the current state only one user with the username
cat lady has added
videos. Both videos are in the
/cats directory owned by
cat lady. The file
/cats/1.mp4 can be viewed by anyone (
/cats/2.mp4 has no extra
sharing options, and can therefore only be viewed by its owner,
cat lady. The
relation tuple definitions are located in the
Now you can open a second terminal to run the queries against, just like the video service client would do. In this example we will use the Keto CLI client.
If you want to run the Keto CLI within Docker, set the alias
in your terminal session. Alternatively, you need to set the remote endpoint so that the Keto CLI knows where to connect to (not necessary if using Docker):
First off, we get a request by an anonymous user that would like to view
/cats/2.mp4. The client now has to ask Keto if that operation should be
allowed or denied.
We already discussed that this request should be denied, but it is always good to see this in action.
cat lady wants to change some view permissions of
/cats/1.mp4. For this,
the video service application has to show all users that are currently allowed
to view the video. It uses Keto's
expand-API to get these data:
Here we can see the full subject set expansion. The first branch
indicates that every owner of the object is allowed to view
In the next step we see that the object's owners are the owners of
Finally, we see that
cat lady is the owner of
Note that there is no direct relation tuple that would grant
cat lady view
/cats/1.mp4 as this is indirectly defined via the ownership
The special user
* on the other hand was directly granted view access on the
object, as it is a first-level leaf of the expansion tree. The following CLI
command proves that this is the case:
Updating the view permissions will be added here at a later stage.